Wang Lihong – seen here at at a demonstration outside a courthouse – has been arrested for 'creating a disturbance'. Photograph: Andy Wong/AP

Chinese rights advocates are calling for the release of an internet activist who will soon face trial in a case they say highlights the government's fear of increasingly bold public activism.

Supporters say Wang Lihong, 56, represents a growing breed of internet-empowered Chinese ordinary people who mobilise others to fight problems such as corruption and miscarriages of justice.

They say Wang is being punished for her involvement in a street protest in southern China against the prosecution of three bloggers.

"I believe that Wang Lihong has not committed any crime," said Ai Xiaoming, a Guangzhou-based feminist scholar who helped set up a blog calling for Wang's release. "She is someone who has emerged from the internet era … to become an organiser of citizen action."

Wang, held at a detention centre in central Beijing, is expected to be tried in several weeks on the vaguely worded charge of "creating a disturbance". She would plead not guilty, her lawyer Han Yicun said. If convicted she faces up to five years in jail.

The charge is linked to Wang's participation in a demonstration outside a court in Fuzhou city in April last year in support of three bloggers accused of slander after they tried to help an illiterate woman pressure authorities to reinvestigate her daughter's death.

About 30 internet users from around the country travelled to the courthouse, where they waved banners and sang songs. The area was cordoned off and police were stationed around the protesters.

One rights group said Chinese authorities have deemed Wang a threat because she represents a movement to use the internet to organise real-world protests.

"That crucial step of moving protests from online to real social-political space is precisely what worries authorities," said Renee Xia, international director of the rights group Chinese Human Rights Defenders.

A Fuzhou government news office employee with the surname Jiang said on Tuesday that he had not heard about Wang's case.

Public activism in China has surged in recent years, helped by the popularity of microblogs that allow rapid dissemination of information. Bloggers have swung into action on prominent cases such as the mysterious death last Christmas of an activist village leader and a train crash near the eastern city of Wenzhou in July that killed at least 40 people.

Wang joined a handful of activists in publicly celebrating the awarding of the Nobel peace prize to jailed Chinese dissident Liu Xiaobo in October 2010. "I think the most important thing is that every person learns how to be their own citizen and not become someone else's subordinate," Wang told Associated Press in an interview at that time.

"In the past it was always about obeying the orders of a higher authority, saying yes, yes, yes all the time," Wang said. "But now everyone must know their human rights and be able to guarantee this. Only when you have responsible citizens will you have a well-functioning, lawful society."

Wang began pursuing rights issues in 2008 after retiring from a business renovating and renting out basement dwellings, her son Qi Jianxiang, 26, said in an interview. She took it upon herself to investigate reports of injustice that had spread on the Internet, he said.

The cases included Yang Jia, a man who confessed to killing six Shanghai police officers in 2008 in revenge for allegedly being tortured while being interrogated about a possibly stolen bike; and Deng Yujiao, a waitress who was accused of fatally stabbing a party official in 2009 to fend off his demands for sex.

"On the one hand I really admire my mother and feel that someone like her is hard to come by," Qi said. "But on the other hand I'm also very worried because there is no need to end up in this situation just for wanting to help someone."

Wang was detained by Beijing police in late March during a sweeping crackdown on activists as authorities moved to prevent the growth of an Arab-style protest movement. Dissident artist Ai Weiwei, the most prominent target, was recently freed from three months of detention.

Supporters have set up a blog, a Facebook page and a Google online group to inform the public about Wang's case as well as to call for signatures on a petition. Some Chinese Twitter users have replaced their profile photos with pictures of Wang and post messages daily calling for her freedom. A poet has also published a poem on his blog called Search for Wang Lihong.

"Her work sought to defend the law and the rights that the law affords us, including the most simple right of freedom of speech and our right to protest things that we cannot bear to see, things that are unfair," said Zhao Lianhai, an activist previously jailed for protesting and organising a petition about the country's tainted milk scandal.